Sonora Quest Laboratories, the state and the University of Arizona are partnering to create a system that will warn the public when valley fever, a potentially deadly disease, is active.

The fungal infection killed at least 50 Arizonans last year and made thousands more ill. The ages of those affected in Arizona last year ranged from 9 months to 102 years old, with a median age of 55.

People and animals become infected with valley fever (also known as coccidioidomycosis) after inhaling airborne fungal spores that are found naturally in Arizona soil. The respiratory disease is not contagious and cannot be transmitted from animals to humans.

While there’s no foolproof way to prevent valley fever, there are precautions people can take when it’s active, including staying inside and keeping windows and doors closed during dust storms or windy conditions.

The idea for improving valley fever warnings was inspired by Kern County, California, which in September was able to warn the public to be wary of valley fever, said Dr. John Galgiani, director of the UA’s Valley Fever Center for Excellence.

The Kern County warning was based on a several factors, including an uptick in requests for valley fever blood tests, a higher than usual number of tests coming back positive, and visits to emergency rooms.

The Arizona Department of Health Services receives positive laboratory results on a daily basis. Increases in positive reports may be due to a variety of reasons, including increases in testing by health-care providers, state officials say.

Since October, state health officials have been meeting regularly with Sonora Quest to better describe and understand the testing data, looking first at historical records.

“We plan on looking at the percentage of people tested for valley fever who have a positive test. If this percentage increases, it may be a better indicator for actual increases in disease occurrence,” department spokesman Benjamin Palmer wrote in an email.

“However, this work is in the early stages, so it will take time to examine and understand the data and possible uses.”

Adding information on tests being ordered, and combining that analysis with the percentage coming back positive and other community factors, could be helpful in predicting when the disease is active, Galgiani said.

Still, a lag time is inevitable. There is a one- to four-week incubation period between exposure and the onset of symptoms, valley fever experts say.

Thousands of cases of valley fever — more than 7,000 last year — are reported to the Department of Health Services annually. People who get ill report symptoms ranging from fatigue, cough and fever to rashes, weight loss and infections of the bones, joints and brain.

The new Sonora Quest effort was established to improve valley fever detection, accurate infection diagnosis and to better address the needs of the state’s at-risk population, officials say.

Those at higher risk of developing a serious infection include anyone who lives or visits areas where the fungus thrives in the soil (residents or travelers primarily to Southern Arizona and California); people with a weakened immune system; those taking immunosuppressing treatments for an organ transplant or rheumatologic disease; or women who are pregnant.

The valley fever-causing coccidioides fungus live primarily in the Southwest, and about two-thirds of the cases reported annually occur in a corridor between Tucson and Phoenix.

Contact health reporter Stephanie Innes at 573-4134 or email sinnes@tucson.com. On Twitter: @stephanieinnes